Effect of Rotor Tip Speed and Stator Sweep on Rotor-Stator Interaction

2004 ◽  
Author(s):  
Oliver V. Atassi ◽  
Christopher M. Hall
Keyword(s):  
Diagnostic Test ◽  
Correlation Length ◽  
Radial Distribution ◽  
Noise Source ◽  
Guide Vane ◽  
Phase Variation ◽  
Periodic Component ◽  
Source Regions ◽  
Rotor Stator Interaction ◽  
Radial Phase

Data taken in the Source Diagnostic Test of the unsteady pressure on a fan-exit guide vane is analyzed to identify the dominant noise producing regions on the vane. The dominant noise source regions of the vane are identified as the outer fifty percent span of the vane. The sensitivity of this result to fan tip speed and exit guide vane sweep is studied. Sweep is seen to decrease the radial correlation length of the unsteady vane response and hence decrease the noise produced by wake-vane interaction. Results for the periodic component of the fan wakes show that the magnitude of the wake harmonics is largest in the outer fifty percent span of the duct and the radial phase variation is largest in the hub region. These results demonstrate a strong cause and effect relationship between the radial distribution of the wake harmonics and the dominant noise producing regions on the fan-exit guide vane.

Radial phase variation computing: a tool to improve flaw detection in optical diagnosis by shearographic images

2013 ◽  
Vol 52 (22) ◽  
pp. 5460 ◽  
Author(s):  
Analucia V. Fantin ◽  
Daniel P. Willemann ◽  
Matias R. Viotti ◽  
Armando Albertazzi
Keyword(s):  
Flaw Detection ◽  
Phase Variation ◽  
Optical Diagnosis ◽  
Radial Phase

scholarly journals Numerical analysis of pressure fluctuation in a multiphase rotodynamic pump with air–water two-phase flow

2019 ◽  
Vol 74 ◽  
pp. 18 ◽  
Author(s):  
Wenwu Zhang ◽  
Zhiyi Yu ◽  
Yongjiang Li ◽  
Jianxin Yang ◽  
Qing Ye
Keyword(s):  
Pressure Fluctuation ◽  
Two Phase Flow ◽  
Guide Vane ◽  
Fluid Model ◽  
Pure Water ◽  
Maximum Amplitude ◽  
Phase Flow ◽  
Two Phase ◽  
Rotor Stator Interaction ◽  
Two Fluid Model

Pressure fluctuation in single-phase pumps has been studied widely, while less attention has been paid to research on multiphase pumps that are commonly used in the petroleum chemical industry. Therefore, this study investigates the pressure fluctuation for a multiphase rotodynamic pump handling air–water two-phase flow. Simulations based on the Euler two-fluid model were carried out using ANSYS_CFX16.0 at different Inlet Gas Void Fractions (IGVFs) and various flow rate values. Under conditions of IGVF = 0% (pure water) and IGVF = 15%, the accuracy of the numerical method was tested by comparing the experimental data. The results showed that the rotor–stator interaction was still the main generation driver of pressure fluctuation in gas–liquid two-phase pumps. However, the fluctuation near the impeller outlet ascribe to the rotor–stator interaction was weakened by the complex gas–liquid flow. For the different IGVF, the variation trend of fluctuation was similar along the streamwise direction. That is, the fluctuation in the impeller increased before decreasing, while in the guide vane it decreased gradually. Also, the fluctuation in the guide vane was generally greater than for the impeller and the maximum amplitude appeared in the vicinity of guide vane inlet.

Localization of tire/pavement noise source regions

2008 ◽  
Vol 56 (5) ◽  
pp. 318 ◽  
Author(s):  
Richard J. Ruhala ◽  
Courtney B. Burroughs
Keyword(s):  
Noise Source ◽  
Source Regions ◽  
Pavement Noise

scholarly journals Experimental Investigation of Rotor-Stator Interaction in Axial-Flow Turbines and Compressors

1998 ◽  
Vol 4 (4) ◽  
pp. 217-231
Author(s):  
Heinz E. Gallus
Keyword(s):  
Unsteady Flow ◽  
Total Pressure ◽  
Vector Fields ◽  
Guide Vane ◽  
Axial Flow ◽  
Tip Clearance ◽  
Inlet Guide Vane ◽  
Flow Measurements ◽  
Rotor Stator Interaction ◽  
Flow Compressor

Detailed results of unsteady flow measurements in a stator-rotor-stator assembly of an axial-flow turbine as well as an inlet guide vane-rotor-stator formation of an axial-flow compressor are presented in this paper.The measurements include the time-dependent 3-D velocity vector fields in the axial gaps between the blade rows by means of triple-hot wire-technique, furthermore the total pressure field downstream of the blade rows by means of semiconductor total pressure probes and the unsteady flow field determination in the rotor passages by LDV-technique. Special semiconductor pressure measurements along the casing all over the rotor tip clearance permit detailed discussion of the rotor tip clearance flows.The conclusion of the measured data provides a new and very instructive view of the physics of the unsteady blade-row interaction in axial-flow turbines and compressors.

A Nonaxisymmetric Endwall Design Methodology for Turbine Nozzle Guide Vanes and its Computational Fluid Dynamics Evaluation

2011 ◽  
Author(s):  
O¨zhan H. Turgut ◽  
Cengiz Camcı
Keyword(s):  
Total Pressure ◽  
Design Methodology ◽  
Computational Study ◽  
Guide Vane ◽  
Leading Edge ◽  
Cavity Flow ◽  
Subsequent Paper ◽  
Rotor Stator Interaction ◽  
Endwall Contouring ◽  
Nozzle Guide

Nonaxisymmetric endwall contouring has recently become one of the ways to minimize the secondary flow related losses in a turbine nozzle guide vane (NGV) passage. In this study, a specific nonaxisymmetric endwall contouring design methodology is introduced. Fourier series based splines at different axial locations are generated and combined with the help of stream-wise B-splines within solid modeling program. Eight different contoured endwalls are presented in this paper. Computational study of these designs are performed by the finite-volume flow solver. The SST k–ω turbulence model is selected and a body-fitted structured grid is used. Total pressure distribution at the NGV exit shows that contouring the endwall effectively changes the results. Among from these various designs, the most promising one is with the contouring extended in the upstream of the vane leading edge. Mass-averaged value of 3.2% total pressure loss reduction is achieved at the NGV exit plane. The current study was performed in a rotating turbine rig simulating a state of the art HP turbine stage. An NGV only simulation is performed. This approach is helpful in isolating rotor-stator influence and the possible upstream flow modifications of the rim seal cavity flow existing in the rotating turbine research rig. The investigation including the rotor-stator interaction and rim seal cavity flow is the topic of a subsequent paper currently under progress.

scholarly journals Measurement of Unsteady Pressure Due to Rotor-Stator Interaction in Pump Guide Vane Passage.

1995 ◽  
Vol 61 (586) ◽  
pp. 2157-2164 ◽  
Author(s):  
Mitsuo Uno ◽  
Hiroshi Tsukamoto ◽  
Yuji Nagai ◽  
Hiroki Fukuno ◽  
Nobunari Hamafuku ◽  
...  
Keyword(s):  
Guide Vane ◽  
Unsteady Pressure ◽  
Rotor Stator Interaction

The action mechanism of rotor–stator interaction on the hydraulic and hydroacoustic characteristics of the guide vane in a jet centrifugal pump

2020 ◽  
Vol 34 (34) ◽  
pp. 2050396
Author(s):  
Rong Guo ◽  
Rennian Li ◽  
Renhui Zhang ◽  
Wei Han
Keyword(s):  
Flow Field ◽  
Transient Flow ◽  
Guide Vane ◽  
Centrifugal Pumps ◽  
Action Mechanism ◽  
Exterior Field ◽  
Outlet Angle ◽  
Rotor Stator Interaction ◽  
Wrap Angle ◽  
Hydrodynamic Noise

The aim of this study was to investigate the action mechanism of the rotor–stator interaction (RSI) in the transient flow field and hydrodynamic noise field of the guide vane in jet centrifugal pumps (JCPs). The numerical method of CFD (computational fluid dynamics), coupled with CFA (computational fluid acoustics), was used to analyze the correlation between the impeller parameters and the flow/sound characteristics of the guide vane. The results show that on the inlet surface of the guide vane, an impeller with fewer blades, a smaller wrap angle, a smaller outlet angle and a smaller outlet diameter is beneficial for reducing the pressure fluctuation intensity. When the guide vane geometry is constant, the evolution processes of the transient flow field inside the static and dynamic cascades are mainly related to the blade number and speed of the impeller. An impeller with more blades, a larger wrap angle, a smaller outlet angle and a smaller outlet diameter is beneficial for improving the flow field distribution in the dynamic and static cascades. The hydrodynamic noise in the interior field is mainly related to the fluctuation characteristics of the transient flow field, but that in the exterior field is related not only to the fluctuation characteristics of the transient flow field, but also to the structural properties of the JCP pump body. The hydrodynamic noise in the exterior field presents an obvious dipole symmetrical distribution on the meridional plane, and the minimum value appears in the direction of the rotation axis because of the symmetrical structural characteristics of the pump body. The modal-shaped features of the JCP lead to a sidelobe phenomenon on the sagittal plane.

Numerical analysis of hub cavity leakage

2019 ◽  
Vol 91 (8) ◽  
pp. 1086-1092
Author(s):  
Ye Xia ◽  
Yadong Xie ◽  
Danwang Li ◽  
Wenjie Wang
Keyword(s):  
Guide Vane ◽  
Suction Surface ◽  
Content Type ◽  
Tooth Structure ◽  
Aerodynamic Loss ◽  
Rotor Stator Interaction ◽  
Overall Performance ◽  
The Impact ◽  
Bypass Ratio ◽  
Practical Implications

Purpose This paper aims to predict the effect of the hub cavity leakage on the overall performance with numerical simulations in the fan/booster of a high bypass ratio turbofan engine. Design/methodology/approach Simulations are conducted for leakage at the fan, the outlet of guide vane and the three-stage booster, as well as hub leakage (contain cavities and sealing). The results obtained are compared to the corresponding simulations without hub leakage. Findings The rotor/stator interaction locations are evaluated to discover a better location. The results show that the seal tooth structure produces secondary flow and turbulence in the root of blade suction surface, which increases the aerodynamic loss. The sealing clearance should be controlled to shrink the turbulent region and decrease the leakage. Practical implications This work can provide a theoretical guidance and technical support for the compressor design, which avoid many repeated manufactures and reduce waste of resources. Originality/value This work improves the understanding of the impact mechanism of hub cavity leakage on the performance when the clearance size of seal is variable.

scholarly journals On the Rotor Stator Interaction Effects of Low Specific Speed Francis Turbines

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Einar Agnalt ◽  
Igor Iliev ◽  
Bjørn W. Solemslie ◽  
Ole G. Dahlhaug
Keyword(s):  
Guide Vane ◽  
Pressure Fluctuations ◽  
Angular Position ◽  
Pressure Sensors ◽  
Pump Turbine ◽  
Blade Loading ◽  
Loading Case ◽  
Rotor Stator Interaction ◽  
Low Specific Speed ◽  
Specific Speed

The rotor stator interaction in a low specific speed Francis model turbine and a pump-turbine is analyzed utilizing pressure sensors in the vaneless space and in the guide vane cascade. The measurements are analyzed relative to the runner angular position by utilizing an absolute encoder mounted on the shaft end. From the literature, the pressure in the analyzed area is known to be a combination of two effects: the rotating runner pressure and the throttling of the guide vane channels. The measured pressure is fitted to a mathematical pressure model to separate the two effects for two different runners. One turbine with 15+15 splitter blades and full-length blades and one pump-turbine with six blades are investigated. The blade loading on the two runners is different, giving different input for the pressure model. The main findings show that the pressure fluctuations in the guide vane cascade are mainly controlled by throttling for the low blade loading case and the rotating runner pressure for the higher blade loading case.

Fan Noise Source Diagnostic Test -- Far-field Acoustic Results

2002 ◽  
Author(s):  
Richard Woodward ◽  
Christopher Hughes ◽  
Robert Jeracki ◽  
Christopher Miller
Keyword(s):  
Diagnostic Test ◽  
Noise Source ◽  
Far Field ◽  
Fan Noise
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